Weird double image in motion

Everything about displays and monitors. 120Hz, 144Hz, 240Hz, 4K, 1440p, input lag, display shopping, monitor purchase decisions, compare, versus, debate, and more. Questions? Just ask!
Post Reply
eyeStrain
Posts: 5
Joined: 08 Nov 2022, 19:38

Weird double image in motion

Post by eyeStrain » 10 Nov 2022, 01:29

Hello everyone. Hope you experts can help me out with this :D


Earlier this year I upgraded from a Sony 60Hz 1080p TV to a Samsung 120hz 4K TV, and I have been struggling to adapt.

I find that motion overall looks weird.

It’s most noticeable on panning shots, and especially with thin (street signs etc), or fast moving objects.

This video is a great example to illustrate what I mean.

With videos like this, motion looks totally different between this TV and all my other displays.

In my new TV, as the ball goes faster, it seems to multiply into many distinct slightly transparent balls (like a venn diagram), giving it this weird kind of double image effect, instead of distorting into a blurry oval shape (like the usual motion blur that I'm used to).

While in some cases it's barely noticeable, for some games and content it can get very uncomfortable.
(such as first/third person games with fast moving cameras etc)


This text I found online is also a good description of what it looks like:
OK, after thinking about this "30hz double imageproblem" you are speaking of, I just fired up the RE4 game on the 4500 and looked around a bit. After about 5 minutes of looking about in a room with white columns, I think I understand what you are talking about. Take for instance, a light colored vertical column in a dark room. In a 30fps game, if you look around/pan the screen and follow the column with your eyes, you can see "two" of them as they move-- the faster they move, the wider apart the two images appear. The slower they move, the closer the two images are, and they converge when you completely stop moving/scrolling.
Except it happens at 60fps.


I wonder if this could have something to do with the TV having a fast response time?

And if so, can anything be done about it?
Sadly, there’s no option in the TV to choose between faster and slower response time, like monitors usually have.
Any chance that would be possible with something like the service menu…?


VRR
Something else I should mention:

I recently noticed that, for some reason, turning on VRR on the PS5 seems to 'fix' the issue. Suddenly the motion looks how I’m used to, with moving objects blurring together rather than becoming two distinct images.

This works regardless of the game having VRR support, simply by ‘forcing’ VRR by turning on “apply to unsupported games”.

As long as the TV's game bar shows that VRR is ON, motion looks different, even though the refresh rate shows a static 59/60Hz.
IMG_5488.JPEG
IMG_5488.JPEG (249.61 KiB) Viewed 3691 times
Image

Sadly, this ‘forced VRR’ isn’t available for PS4 games.

But this does shows that under certain conditions, this TV *can* produce motion that look ‘normal’ to me (what my eyes are used to), and that doesn't cause discomfort. But it seems to be ‘locked’ behind some internal, hidden setting.

Any idea why this would happen?


Other things I’ve tried:
- Motion Interpolation ON vs OFF, at different settings
Some settings make it look a bit better, but motion can still look pretty uncomfortable depending on the content. Also, it introduces artifacts.

- BFI on and off
BFI makes motion look *way* clearer, but introduces flickering which is uncomfortable in its own right.


Anyway just wanna end this by thanking this community and anyone willing to help.
I've been reading a lot of a BlurBuster's articles, learning more about the different kinds of motion blur and how our eyes and display technologies work, to try and figure out what exactly it is that's bothering me.

User avatar
Chief Blur Buster
Site Admin
Posts: 11647
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

Re: Weird double image in motion

Post by Chief Blur Buster » 10 Nov 2022, 03:12

- Your TV may be using PWM-dimming or double strobing 120Hz.
Try testing 100% brightness (maximum backlight brightness) and seeing if things go back to normal.

You may need to sell your Samsung since it's possibly got a backlight that permanently flickers outside VRR.

Remember, the number of duplicate images is your refresh rate multiplied by image duplicates you see, if you're doing framerate=Hz, it means your backlight is strobing at # x Hz where # is number of duplicate images. So your Samsung has a permanent 120Hz strobe backlight that cannot be disabled except in VRR mode.

Image

But see if adjusting brightness to 100% fixes this.

Also maybe post on AVSFORUM, as they may be familiar with that specific model and its artifact.

Failing this, try buying a different model, maybe?
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

eyeStrain
Posts: 5
Joined: 08 Nov 2022, 19:38

Re: Weird double image in motion

Post by eyeStrain » 11 Nov 2022, 16:36

Thank you for the quick reply!
“Your TV may be using PWM-dimming or double strobing 120Hz.
Try testing 100% brightness (maximum backlight brightness) and seeing if things go back to normal.”
Hmm, maybe that could be it.

I tried testing but honestly it's hard to say for sure.
It definitely seems to be an improvement at full brightness, but it doesn’t seem to eliminate the doubling completely like VRR does.

Though the TV does get way too bright at full backlight.
So your Samsung has a permanent 120Hz strobe backlight that cannot be disabled except in VRR mode.
unnamed.png
unnamed.png (47.82 KiB) Viewed 3523 times
Yeah, that seems to be the case. I tested Movie Mode and it also removes the doubling, but it isn’t fit for gaming.

Any idea why VRR would disable the backlight strobing? And why it can't do that outside of VRR mode…
Like, I wonder how the TV handles dimming the backlight while VRR is on 🤔 Would it just strobe at a different frequency?


I was thinking I'm just gonna have to learn to live with this double image, since I don't see myself getting a new TV so soon...
But seeing that VRR fixes the issue gave me some hope.

I wonder if there's a way to 'force' it to always act like that…

Maybe somehow 'tricking' the TV into thinking VRR is always on.
Or if there's a setting that can be changed in the service menu or something…


I'll try asking on AVSFORUM like you said. Once again, thanks a lot.

User avatar
Chief Blur Buster
Site Admin
Posts: 11647
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

Re: Weird double image in motion

Post by Chief Blur Buster » 11 Nov 2022, 16:54

The backlight goes steady-state (no strobe) during VRR mode.

You can try attempting to watch your Netflix / Disney+ / Prime via a laptop/PC/HTPC with VRR turned on. Use NVIDIA Control Panel -> G-SYNC ON for everything (Windowed/fullscreen).

It is a crude band-aid but it works.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

eyeStrain
Posts: 5
Joined: 08 Nov 2022, 19:38

Re: Weird double image in motion

Post by eyeStrain » 14 Nov 2022, 18:34

The backlight goes steady-state (no strobe) during VRR mode.
How would it control the backlight strength then? 🤔
So like, the display *is* capable of dimming without strobing the backlight, but still defaults to doing so?
Seems like a weird choice on their part...

You can try attempting to watch your Netflix / Disney+ / Prime via a laptop/PC/HTPC with VRR turned on. Use NVIDIA Control Panel -> G-SYNC ON for everything (Windowed/fullscreen).
Thanks for the suggestion! I’ll keep it in mind.


Though what bothers me the most is with PS4 games, which are a good chunk of what I play.

For now I guess I'll try using the brightness workaround for those, as it does seem to help at least a bit.

Is there any way can I make the image less bright while keeping the backlight at 100%?
It’s not a huge deal if it affects image quality/contrast a bit.

Would just lowering brightness inside the game’s settings work? And it will keep the backlight PWM-dimming off?
Or is that not how it works?

User avatar
Chief Blur Buster
Site Admin
Posts: 11647
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

Re: Weird double image in motion

Post by Chief Blur Buster » 14 Nov 2022, 21:54

eyeStrain wrote:
14 Nov 2022, 18:34
How would it control the backlight strength then? 🤔
So like, the display *is* capable of dimming without strobing the backlight, but still defaults to doing so?
Seems like a weird choice on their part...
This improves some motion handling for some television material (e.g. sports), which is probably what they prioritized on.
Design decisions can be rather annoying, when they interfere with your gaming.
As you have found out, the best solution for gaming is to enable VRR.
eyeStrain wrote:
14 Nov 2022, 18:34
You can try attempting to watch your Netflix / Disney+ / Prime via a laptop/PC/HTPC with VRR turned on. Use NVIDIA Control Panel -> G-SYNC ON for everything (Windowed/fullscreen).
Thanks for the suggestion! I’ll keep it in mind.
It is an annoyance to have to use a VRR-compatible streaming device, but it is a workaround if you are bothered. The good news is that if you can run at 120Hz from the PC, your 24fps and 60fps material should look de-juddered.
eyeStrain wrote:
14 Nov 2022, 18:34
Would just lowering brightness inside the game’s settings work?
If you disable all dynamic backlight dimming options via the TV menus, then yes that will work.

Then the backlight stays at maximum, and it just uses the software/GPU/graphics for dimming the picture. You lose contrast ratio this way (blacks won't get darker), but you won't get the flicker.

On PC, you can use AMD CCC or NVIDIA Control Panel.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

eyeStrain
Posts: 5
Joined: 08 Nov 2022, 19:38

Re: Weird double image in motion

Post by eyeStrain » 30 Nov 2022, 19:46

Hey so good news I think!

I found this option in the service menu (I think it stands for Force Freesync?)
download (2).png
download (2).png (54.46 KiB) Viewed 3170 times


It seems to be the workaround I was looking for, something to 'trick' the TV into acting like VRR is on.
With this enabled, the Game Bar shows VRR ON even for PS4 games, and the doubling is gone.


Do you know if there's any danger to keeping this on?

I haven't noticed any side effects, but I wanna make sure it's not something that could damage the TV (or the PS5) long term.

eyeStrain
Posts: 5
Joined: 08 Nov 2022, 19:38

Re: Weird double image in motion

Post by eyeStrain » 24 Jan 2024, 13:52

Hey, I have one more question (sorry to necro).

If I dont want to have to deal with this in the future, for my next TV, do I have to get a flicker free TV?

Or just make sure it doesn’t flicker at 120hz?


Or do I just have to get a TV that’s not 120hz? (not sure if refresh rate is related)


My old Sony TV (W600B if I'm not mistaken) isn’t flicker free I think, but it didn’t have this problem.

Though to be honest, I don't even think there are any flicker free models available in my country, especially since Sony doesn't sell TVs here anymore.

Post Reply